LED或灯脉冲发生器电路

LED或灯脉冲发生器电路
LED或灯脉冲发生器电路--LEDorLampPulserAstonishingeffect4.5Vsupply
Parts:R1,R2___________4K71/4WResistorsR3_____________22K1/4WResistorR4______________2M21/4WResistor(SeeNotes)R5_____________10K1/4WResistorR6_____________47R1/4WResistor(SeeNotes)C1______________1F63VPolyesterCapacitorD1_____________5mm.RedLED(SeeNotes)IC1__________LM358LowPowerDualOp-ampQ1___________BC33745V800mANPNTransistorCircuitoperation:ThiscircuitoperatesaLEDinpulsingmode,i.e.theLEDgoesfromoffstate,lightsupgradually,thendimsgradually,etc.Thisoperationmodeisobtainedbyatriangularwavegeneratorformedbytwoop-ampscontainedinaverycheap8pinDILcaseIC.Q1ensurescurrentbuffering,inordertoobtainabetterloaddrive.R4C1arethetimingcomponents:usingthevaluesshowninthepartslist,thetotalperiodisabout4seconds.Notes:ThemostsatisfyingresultsareobtainedadoptingforR4avaluerangingfrom220Kto4M7.AdoptingforR4avaluebelow220K,thepulsingeffectwillbeindistinguishablefromanormalblinkingeffect.TheLEDcanbeanytypeandcolor.Youcanuseafilamentlampinstead,provideditsfeaturesarecomprisedintherange3.2to6V,200mAmax.Usingalampasaload,R6mustbeomitted.Voltagesupplyrangecanbe4to6V:4.5Visthebestcompromise.Don'tsupplythecircuitwithvoltagesexceeding6V:itwillworklessgoodandQ1couldbedamagedwhenalampwasusedastheload.At6Vsupply,increaseR6valueto100Ohm.